Dr. Chirwa

Question 1

Two types of presynaptic Mechanisms?

Answer 1

electrical and chemical

Question 2

Electrical synapse

Answer 2

the movement of electrical current jumping from gap junction to gap junction.

Question 3

Chemical synapse

Answer 3

The movement of neurotransmitters from one neuron to another

Question 4

Post synaptic neurons

Answer 4

Have a slight delay

Question 5

contains electrical vesicles in the presynaptic neuron

Answer 5

chemical synapse

Question 6

Why does chemical synapse take much longer than electrical synapse?

Answer 6

because NT on chemical synapse to to line up with receptors of the post synaptic neuron, then release the presynaptic NT from the synaptic vesicle.

Question 7

Synaptic vesicle

Answer 7

stores NT in vesicles in the presynaptic neuron in chemical synapse.

Question 8

2 millisecond delay

Answer 8

is seen with chemical delay occurs slowly due to neurons aligning releasing and binding of NT

Question 9

1 millisecond delay

Answer 9

seen with electrical delay which occurs quickly through gap junctions

Question 10

Synapsin

Answer 10

anchors group of NT vesicles together

Question 11

Docking

Answer 11

NT being free and going close to the plasmalemma

Question 12

What must occur before NT vesicles release NTs docked on the plasmalemma?

Answer 12

Calcium must enter the neuron through calcium channels.

Question 13

Clathrin

Answer 13

A protein that reclaims back old NT cleaving inward.

Question 14

Dyanamine protein

Answer 14

takes the neck of the Clathrin vesicle so it can be released

Question 15

At rest the presynaptic terminal is negative or positive.

Answer 15

it is negative until an AP occurs the presynaptic terminal becomes more positive (depolarize)

Question 16

When does depolarization occur?

Answer 16

When calcium enter the neuron through calcium channels

Question 17

What type of cells pick up calcium ions in the synaptic cleft?

Answer 17

glial cells

Question 18

What holds syntaxin and synaptobrevin together?

Answer 18

SNAP-25 protein

Question 19

What is the name of the “calcium sensor”?

Answer 19

Synaptotagmin

Question 20

What can happen if BoTx or TeTx is injected in the veins?

Answer 20

it prevents the binding of syntaxin and synaptobrevin and acetocholine can not bind for a long time which can paralyze the diaphragm because it also needs acetylcholine. Patient will need a ventilator

Question 21

Lambert-Eaton Myasthenic syndrome

Question 22

Botulin toxin

Question 23

Tetanus Toxin

Question 24

Which statement regarding metabotropic and ionotropic receptors is true?

Answer 24

Ionotropic receptors have immediate efects; metabotropic receptors
produce long-term efects.

Question 25

Which event is the first in the series of events that take place during chemical synaptic transmission?

Answer 25

Voltage gated Ca2+ channels open

Question 26

In the sequence of events in neurotransmission, which event occurs just after the action potential arrives at the presynaptic terminal?

Answer 26

Influx of Ca2+ into the presynaptic terminal

Question 27

How would application of a Ca2+ channel blocker affect the function of a synapse?

Answer 27

It would eliminate the postsynaptic potential and the presynaptic Ca2+ current.

Question 28

Which protein plays a key role in endocytosis?

Answer 28

Clathrin

Question 29

A scientist wishes to develop a new drug that prevents synaptic communication via neuropeptides but not small molecule neurotransmitters. Which mechanism would be a good target for his drug?

Answer 29

Disruption of fast anterograde axonal transport

Question 30

Which treatment would prevent the release of neurotransmitter from the presynaptic terminal?

Answer 30

A toxin that cleaves synaptobrevin

Question 31

Clostridial Toxin

Answer 31

Cleaves syntaxin, synaptobrevin, SNAP-25

Question 32

The most important factor determining whether a receptor-operated ion channel is inhibitory or excitatory is

Answer 32

whether the permeant ion’s reversal potential is positive or negative to threshold.

Question 33

Which statement about a nicotinic acetylcholine receptor at the neuromuscular junction is accurate?

Answer 33

It has two binding sites, and binding of two molecules ofacetylcholine, one to each site, is required to activate the receptor.

Question 34

Which molecule binds NMDA receptors and prevents the flow of ions at resting and hyper polarized membrane potentals?

Answer 34

Mg2+

Question 35

Which change could be responsible for increasing the amplitude of an excitatory postsynaptic potential (EPSP)?

Answer 35

An increase in the amount of glutamate released into the synapse

Question 36

Cell X fires an action potential and releases GABA onto Cell Y. Assuming only GABAA receptors are present on the postsynaptic membrane, which is at rest at –55mV, which ion is responsible for the changes that would be observed?

Answer 36

Chloride

Question 37

Which statement describes a possible outcome for a neurotransmitter after release into the synaptic clef?

Answer 37

Activation of G-protein-coupled receptor on postsynaptic cell

Question 38

Which has more lasting affect Inotropic or Metabotropic receptors?

Answer 38

Metabotropic receptors

Question 39

Nicotinic Acetylcholinergic Receptor

Answer 39

requires two Ach to bind to its alpha subunit

Question 40

AMPA Receptors

Answer 40

activated by glutamate

Question 41

NMDA Receptor

Answer 41

activated by glutamate and glycine Mg2+ is its gate keeper Depolarization of the membrane kicks Mg2+ out

Question 42

Which receptors produces fast excitatory postsynaptic current

Answer 42

AMPA and NMDA

Question 43

Where does the trigeminal nerve enter the brain?

Answer 43

mid pons